Just as George W Bush announces that the surge in Iraq has opened the door to "strategic victory", evidence is emerging that the US-sponsored Sunni militias that have been at the heart of the surge strategy - the so-called "awakening councils" - are already showing signs of falling apart.

Far more than the extra 30,000 US troops sent to Iraq last year, or the 12-foot high concrete walls and checkpoints that now scar Baghdad and other cities, it has been the creation of the 80,000-strong awakening or "sahwa" militias, based on deals with tribal leaders and defectors from the Sunni-based resistance movement, that has played a crucial role in cutting the number of attacks on the occupation forces in the past few months.

That reduction, which had brought down the US monthly death toll down by about two thirds, was the crucial factor in allowing the US administration to claim that the surge was working and the occupation of Iraq was finally starting to come good - just in time to boost the chances of the pro-war Republican candidate, John McCain, in the presidential election campaign.

But as reported in a Guardian Films documentary for Channel 4 News, leaders of awakening councils across the Sunni areas of Iraq are threatening to go on strike or withdrawing support from the US military because they haven't been paid and aren't getting the jobs in the police and army they had been promised. In some areas, members are leaving the councils in large numbers: 500 have quit in Abu Ghraib and 800 in Tikrit.

The Americans had been paying awakening council members $10 a day to work in harness with US forces, after opposition to the brutality of al-Qaida, fear of sectarian death squads and alarm that Sunni areas were being cut out of the sectarian carve-up presided over by the Shia-dominated Green Zone administration opened the way for US deals with local warlords.

Of course, the mainstream Sunni-based resistance movements, which are opposed to the awakening councils and have always accounted for the majority of attacks on US forces, had also turned against al-Qaida. And another crucial factor in the lower level of violence - the ceasefire by the anti-occupation Shia Mahdi army - has nothing directly to do with the surge at all.

Although the awakening councils have helped buy a political breathing space for the Bush administration, they were always an unstable hotch-potch of groups with different agendas, set up in the teeth of opposition from the nominally independent Iraqi government; and they have already been drawn into sectarian clashes with Shia militias. With growing talk of al-Qaida and Ba'athist infiltration of the councils and hostility from its Shia clients, the US military seems to be losing its enthusiasm for its newfound Sunni proxies.

As one sahwa council leader south of Baghdad told Guardian Films: "When the areas started to cool down and the situation began to get better, the Americans really cooled to us. They had got what they wanted from us."

That came as little surprise to other armed groups in Iraq. In January, a leader of one of the largest Sunni-based resistance groups, the 1920 Revolution Brigades, told me: "The sahwa councils are an unhealthy phenomenon, they are being used as a tool by the US occupation forces. But the US is likely to turn against them in the near future - we don't think the sahwa councils will last."

The current discontent in the awakening councils seems to bear that out. In their current form, they were never more than a short-term fix. But - as a report on the awakening blowback in the current issue of Rolling Stone magazine makes clear - the real danger is that by creating its own Sunni militia, the US has only deepened the fissures opened up by the occupation and laid the foundations for future violent sectarian conflict.